Roof mounting assembly

ABSTRACT

An apparatus for securing a roof-mounted structure to a roof is disclosed. The apparatus comprises: a shaft extending along a longitudinal shaft axis and including a first end opposing a second end; the first end including a roof fastening portion; the second end including a drive part and an anchor portion for securing the roof-mounted structure to the shaft; and the shaft including a radially projecting shoulder surface disposed between the first and second ends and oriented toward the first end.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/516,173, filed Mar. 30, 2011, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The embodiments disclosed herein relate in general to mountingassemblies and in particular to an apparatus and method for securing aroof-mounted structure to a roof.

BACKGROUND

A solar panel (also called a “photovoltaic panel”) is an electricallyinterconnected assembly of solar cells used to generate electric powerfrom sunlight that are mounted within a protective case. Owing to therelatively low power output efficiencies of current commerciallyavailable solar cells, several solar panels are typically required togenerate a meaningful supply of electricity for use in commercial andresidential applications. The panels are relatively large, heavywatertight structures and must be firmly secured to the buildingstructure so as not to damage the structure itself or disrupt thewatertight integrity of the roof. This is typically accomplished throughthe use of a plurality of mounting brackets or other mounting assembliesthat connect the panels directly to the roof structure. In addition tofirmly supporting the weight and size of the panels, the mounts mustalso allow the panels to be efficiently positioned to receive sunlightand must further be strong enough to withstand the adverse climaticelements that the roof itself must endure all year round, includinghigh-winds, snow, ice, leaves and branches, etc.

Solar panels for residential use have been commercially available fordecades, but only recently have solar cells become sufficiently powerefficient and cost effective to compete with more conventional energysources. Although the power savings resulting from a solar panelinstallation may not be realized for many years, the interest in solarenergy has only grown in recent years and this has resulted in a sharpincrease in the number of solar panel installations to residential homesand commercial buildings. To keep up with the busy demand for suchinstallations, there has been much thought regarding the speed andefficiency of the installation process, including the tools and hardwareused to install such a solar panel array to a roof structure keeping inmind the necessary safety requirements and local building codes. Animportant area of interest in this regard is the mounting assemblyitself that is used to mechanically secure the panels to the roofstructure.

The mounting assembly is arguably the most important component of theinstallation because each mount must provide a strong, watertightconnection to the roof, must be adaptable to accommodate the greatestnumber of roofing structures and surface materials, should below-profile, low in cost, and perhaps most importantly should be quickand easy to install and provide consistent predictable results. Thespeed for installation of these mounts is important because usually manyof them have to be installed. A typical residential solar panelinstallation will require several mounts to be secured to the roofstructure, so the time required to install a single mount becomes animportant indicator in determining the time required to complete theinstallation project. The quicker to install one mount, the less timerequired to install many mounts. As to be expected, there are severaldifferent types of roof-mount assemblies commercially available today,but many appear to be complicated, costly and apparently require arelatively long time to install.

To illustrate some of the benefits of the present invention, an exampleof a commonly used prior art roof mounting assembly 10 is shown in FIGS.1, 2 and 3 (labeled “Prior Art”). For this example, a roof 36 is shownincluding composition tiles 37, a protective layer 38 (tar paper), asupport layer 39 (plywood) and framing rafters 40. Of course other typesof mounts and other roof structures exist. The assembly 10 shown inthese Figures is commercially known as a “FastJack” (a registeredTrademark of Professional Solar Products, Inc.) and is available fromProfessional Solar Products, Inc., a company located in Oxnard, Calif.

As shown in the “Prior Art” Figures, the FastJack includes amachined-aluminum mounting block 12, a lag bolt 14, a coupler 16, aflashing element 18, a rubber sealing boot 20 and a connector bolt 22used to attach a rail 24 to the coupler 16, as described below. Mountingblock 12 is made from solid aluminum and includes a counter-bore 25 forreceiving both the lag bolt 14, which is used to secure the mountingblock 12 to the roof 36, and the coupler 16, which receives theconnector bolt 22 to connect the rail 24 to the assembly 10. Coupler 16includes external threads 26 at one end and a threaded bore 28 at anopposing end. The threaded bore 28 is sized and shaped to engage thethreads of the connector bolt 22, whereas the external threads 26selectively engage the threads 27 formed within the counter-bore 25. Theflashing element 18 is somewhat conical in shape, with an integrallyformed flat base 30 and an open upper end 32 defining a rim 34. Wheninstalled to a roof, flashing element 18 is positioned around themounting block 12, coupler 16, connector bolt 22 and the lag bolt 14,with flat base 30 securely nestled under upper tiles or shingles 37, asshown in FIG. 3 (Prior Art). Rubber sealing boot 20 is also conical inshape and includes a lower end 42 opposing and an upper end 44. Thelower end 42 is secured along the rim 34 to form a watertight seal. Theupper end 44 includes an opening 46 that is sized and shaped to snuglyreceive the coupler 16 and thereby form a second watertight seal.

The following steps describe the installation of a mounting assembly 10:

-   1) Locate and mark the location of the roof rafters 40, for example    by using a stud finder and chalk lines;-   2) Mark the location on the roof for each mount, for example by    using a measuring tape and chalk lines;-   3) Drill an appropriately sized pilot hole for lag bolt 14 at each    mark; the installer must drill straight (i.e., square with respect    to a surface of the roof 36) into the roof 36 and into the    underlying rafters 40;-   4) Position the mounting block 12 so that the counter-bore 25 aligns    with the pilot hole;-   5) Secure the lag bolt 14 through the counter-bore 25 of the    mounting block 12 and into the roof 36 so that the mounting block 12    becomes firmly secured to the surface of the roof 36;-   6) Secure the coupler 16 to the counter-bore 25 of the mounting    block 12 by engaging the threads 26 to the threads 27;-   7) Position the flashing 18 over the secured mounting block 12 and    use a flat bar to lift composition tiles or shingles 37 located    above the mounting block 12 so that the flat base 30 of the flashing    18 can be nested below the upper tiles 37;-   8) Position the opening 46 of the rubber sealing boot 20 around the    coupler 16 so that the upper end of the coupler 16 protrudes above    the boot 20; and-   9) Use the connection bolt 22 to secure a rail member 24 to the    coupler 16.

The prior art mounting assembly 10 described above is made up of severalinterconnecting components that have to be assembled in place on a roofsurface, which is typically slanted. This is difficult for an installerbecause the installer must keep all the parts on hand on the roof andmust carefully assemble the mounting assembly in place. Parts can easilyslip and fall off the roof causing delay and possibly injury. Theinstaller doesn't want to deal with this. The quicker the installer cansecure the mounts to the roof, the less time the installer has to be onthe roof and the safer the overall job will be. Also, so manyinterconnecting parts have to be manufactured to a relatively highdegree of accuracy and this can only result in potential alignmentissues during assembly (on the roof) and an increase in cost ofmanufacture.

Applicant has recognized a need for a simple, low-part roof mountingassembly that is very quick and easy to install on a roof, yet meets allthe necessary supportive and sealing requirements. Such a mountingassembly would result in a safer installation since the installer wouldnot be required to remain on the roof for long periods of time and wouldnot have to perform relatively complicated assembly while perched in aprecarious position on the roof.

SUMMARY

An embodiment of a roof-mounting assembly and a method of use aredisclosed herein. In a preferred use, the disclosed mounting assemblycan be used for securing a solar panel to a roof of the type thatincludes roof tiles and an underlying support structure.

In one aspect, an apparatus for securing a roof-mounted structure to aroof comprises a shaft. The shaft extends along a longitudinal shaftaxis and includes a first end opposing a second end. The first endincludes a roof fastening portion, and the second end includes a drivepart and an anchor portion for securing the roof-mounted structure tothe shaft. The shaft further includes a radially projecting shouldersurface disposed between the first and second ends and oriented towardthe first end. According to this aspect, the apparatus can optionallyinclude a first rigid washer. The first rigid washer has a first surfaceopposing a second surface and defines a through aperture sized toreceive the roof fastening portion of the shaft, and at least a portionof the first surface is configured to engage the shoulder surface.

In another aspect, a method of securing a roof mounted structure to aroof having at least one roof tile overlying a roof support structureusing a shaft and a washer is described. The shaft includes a rooffastening portion disposed at a first end of the shaft, a drive part andan anchor portion disposed at a second end of the shaft opposing thefirst end, and an integrally formed radially projecting shoulder surfacedisposed between the first and second ends and oriented toward the firstend. The washer has a first surface opposing a second surface anddefines a through aperture sized to receive the roof fastening portionof the shaft. The method comprises positioning the second surface of thewasher adjacent to the roof and axially aligning the roof fasteningportion with the through aperture, engaging the drive part to drive theroof fastening portion through the roof tiles and into the roof supportstructure such that the shoulder surface engages the first surface ofthe washer to urge the washer towards the roof and provide a watertightseal between the second surface and the at least one roof tile, andsecuring a roof mounted structure to the anchor portion.

In yet another aspect, an apparatus for securing a roof-mountedstructure to a roof having a plurality of roof tiles overlying a roofsupport structure comprises a shaft and a washer. The shaft has a shaftdiameter and extends along a longitudinal shaft axis and includes afirst end opposing a second end. The first end includes a roof fasteningportion having external wood threads configured for threaded engagementwith the roof support structure. The second end includes a screw driveand an anchor portion, the screw drive having a head with a headdiameter equal to or less then the shaft diameter and configured forengagement with a drive socket and the anchor portion having exteriormachine screw threads configured for threaded engagement with theroof-mounted structure. A flange is integrally formed with the shaft anddisposed between the first and second ends, the flange projectingradially from the shaft to define a shoulder surface oriented toward thefirst end. The washer has a first surface opposing a second surface, anddefines a through aperture sized to receive the roof fastening portionof the shaft. At least a portion of the first surface is configured toengage the shoulder surface and the second surface is configured toprovide a watertight seal between the washer and at least one of theroof tiles.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects of the disclosed embodiment include providing a watertightmounting assembly for mounting equipment on top of a roof, and providingsuch a mounting assembly that uses few parts and is quick and easy toinstall on a roof.

These and other objects, features, advantages and other uses of thepresent apparatus and method will become more apparent by referring tothe following detailed description and drawings in which:

FIG. 1, labeled “Prior Art,” is an exploded perspective view of a priorart roof mounting assembly including a mounting block, a lag bolt, acoupler, a flashing element, a sealing boot and a connector bolt;

FIG. 2, labeled “Prior Art,” includes an exploded perspective view ofthe prior art roof mounting assembly of FIG. 1 before assembly andattachment to a roof surface, and includes a perspective view of a fullyassembled and secured mounting assembly;

FIG. 3, labeled “Prior Art,” is a sectional perspective view of thefully assembled and secured mounting assembly of FIGS. 1 and 2 showingdetails of the sealing relationship between the flashing element and theroof surface;

FIG. 4 is a perspective assembly view of a simplified roof mountingassembly according to an embodiment of the present invention prior tobeing installed to a roof;

FIG. 5 is a sectional side view of the roof mounting assembly of FIG. 4installed to a roof;

FIG. 6 is perspective view of the roof mounting assembly of FIG. 5showing details of its securement to the roof; and

FIG. 7 is a partial sectional perspective view of the roof mountingassembly of FIG. 6, showing details of a compression washer and a seal.

DETAILED DESCRIPTION

A roof mounting assembly for securing a roof mounted structure, such asa solar panel, to a roof of the type that includes tiles and anunderlying support structure is described below.

Referring to FIGS. 4-7, a mounting assembly 100 is shown. The mountingassembly 100 includes relatively few parts, including a hanger bolt 102,a first rigid washer 104 and a second sealing washer 107. The hangerbolt 102 includes a shaft 108 extending along a longitudinal shaft axis109, with a first proximal end 112 opposing a second proximal end 116.The first end 112 includes a roof fastening portion 110 configured forsecurely fastening the shaft 108 to a roof. In the illustrated example,the roof fastening portion 110 includes external wood threads. However,other configurations know by those skilled in the art can be used forthe roof fastening portion 110. For example, the roof fastening portion110 can have threads of any configuration, or can alternatively be pinshaped. The first end 112 can further include a thread cutting portion120, for example a self-boring cutting edge, at a tip 118. The secondend 116 includes an anchor portion 114 that can be configured forengagement to a roof mounted structure (not shown). As shown, the anchorportion 114 can include external machine screw anchoring threads,although other configurations know by those skilled in the art can beused for the anchor portion 114.

The second end 116 further includes a drive part 122. The drive part isillustrated as in integrally formed drive head configured for engagementwith a drive socket (not shown) that can be secured to an appropriatepowered drive tool, such as a powered screwdriver or an impact hammer(not shown). In the illustrated embodiment of a hanger bolt 102 wherethe roof fastening portion 110 includes external threads, the drive headcan be utilized to easily drive the bolt 102 into a roof structure at adesired angle and/or to remove the bolt 102 after it has been driveninto a roof structure. The drive head is preferably shaped as a hexdrive, but may be configured as any appropriately shaped drive, such astriangular drive, square drive, Torx® or other drives known by thoseskilled in the art. Where, as shown, the anchor portion 114 includesexternal anchoring threads, a diameter of the drive part 122 can besmaller than a diameter of the anchor portion 114 to allow engagementbetween the anchoring threads and an internally threaded component.

The shaft 108 includes a radially projecting shoulder surface 123disposed between the first end 112 and the second end 116. The radiallyprojecting shoulder surface 123 is oriented towards the first end 112and configured to engage at least a portion of a first surface 103 of arigid washer 104 positioned on the shaft 108 between the roof fasteningportion 110 and the shoulder surface 123. The shoulder surface 123 isillustrated as being orthogonal to the shaft axis 109, but couldalternatively be sloped or arcuate. In a preferred configuration, thefirst end 112 has a first shaft diameter adjacent the shoulder surface123, and the shoulder surface 123 is defined by a flange 124. In theillustrated embodiment, the flange 124 is integrally formed with theshaft 108 and a diameter of the flange 124 is greater than the firstshaft diameter. The flange 124 can be located at a predeterminedlocation along the shaft 108 between the roof fastening portion 110 andthe anchor portion 114, such that the anchor portions 114 of a pluralityof mounting assemblies 100 would each extend a uniform distance from aroof structure when installed.

The hanger bolt 102 is preferably made from a strong appropriate metal,such as steel, but can be made from other materials, such as appropriatealloys, aluminum or stainless steel. Regardless of the material used,the hanger bolt 102 is preferably further corrosion treated, ifnecessary (depending on the material), such as by anodizing, galvanizingor plastic coating the bolt 102, by using a suitable paint, or by usingother corrosion treatments. Obviously, most types of stainless steel arenaturally resistant to corrosion and may require no protective coatingor other corrosion treatment.

The hanger bolt 102 can be any appropriate size depending on thespecific application and requirements. For most solar panelapplications, Applicant prefers that hanger bolt 102 be about 153 mmlong, with the shaft 108 having a diameter of about 7 mm. Where theanchor portion 114 and the roof fastening portion 110 are threaded, itis also preferred that both the anchor portion 114 and the rooffastening portion 110 be about 65 mm long and that the flange 124 beabout 3 mm thick with an approximately 12 mm diameter.

The first rigid washer 104 is preferably made from a strong material,such as a metal, for example steel or stainless steel. As with thehanger bolt 102, the first washer 104 is preferably treated to resistcorrosion. The first washer 104 defines a central opening 105, which isa through aperture sized to receive the roof fastening portion 110 ofthe shaft 108. That is, the central opening 105 is sized slightlygreater than a diameter the roof fastening portion 110. The centralopening 105 is also sized less than the diameter of the flange 124, suchthat the shoulder surface 123 engages the first surface 103 when axiallyaligned with the first washer 104. A thickness of the first washer 104is about 8 mm, and the first washer 104 is preferably slightly concavewith an outer diameter of about 76.2 mm and an inner diameter of about8.6 mm.

The second sealing washer 107 can be disposed on the shaft 108 between aroof structure and the first washer 104. The second sealing washer 107is constructed from a compliant material configured to provide awatertight seal when a second surface 113 of the second sealing washer107 is urged towards a roof structure when a first surface 111 of thesecond sealing washer 107 is engaged by a second surface 106 of thefirst washer 104 as the shoulder surface 123 engages the first surface103 of the first washer 104. The second sealing washer 107 is preferablymade from an appropriate synthetic rubber, such as an EPDM (ethylenepropylene diene Monomer—an M M-class rubber) having a durometer rangebetween 60 and 80, and includes dimensions similar to those of the firstwasher 104—that is, an outer diameter of about 76.2 mm and an innerdiameter of about 8.6 mm. However, the second sealing washer 107preferably has a thickness of about 3.2 mm. Of course all thesedimensions can and will vary depending on the particular application andspecific requirements.

Although the first washer 104 and the second sealing washer 107 areillustrated as separate components, the second sealing washer 107 can bebonded to the first washer 104, or the first washer 104 can be formedintegrally with a suitable compliant material. For example, the firstwasher 104 can be provided with a rubber layer that can be forced intosealing contact with a roof structure by engagement of the flange 124with the first surface 103 when the shaft 108 is driven into the roofstructure. Use of a conventional EPDM bonded stainless steel washer 126is illustrated in FIGS. 5-7. The washer 126 has a central opening 127,and an EPDM rubber layer 128 is effectively bonded to one side of astainless steel concave compression washer 130.

Referring now to FIGS. 5, 6 and 7, the mounting assembly 100 is shownsecured to a roof structure 132. For the purpose of explaining theinstallation procedure of the present invention, roof 132 includescomposite roof tiles 134 (e.g., asphalt shingles) and an underlyingsupport layer 136, which is typically made from ½″ plywood. Locatedbetween the support layer 136 and the roof tiles 134 is awater-impervious layer 138, such as tar-paper or an appropriate plasticlayer. As in conventional framing, rafter beams 142 are positioned belowsupport layer 136 and are generally spaced a regular distance from eachother (usually 16, 18, or 24 inches, measured between centers).

In use of the illustrated embodiment of the present invention:

-   1) The installer first measures out the roof and marks the locations    where the mounting assemblies 100 are to be secured. The installer    must make sure that each mark aligns perfectly with an underlying    rafter beam 142.-   2) The installer uses a drill (usually with an attached guide) and    an appropriately sized drill bit to drill a pilot hole 144 through    the roof tiles 134, the support layer 136, the water-impervious    layer 138 and partway through the underlying rafter beam 142. The    depth of pilot hole 144 from the surface of shingles 134 should be    equal to the distance between the tip 118 the shoulder surface 123    defined by the flange 124.-   3) The bonded washer 126 is positioned over the roof. The installer    then aligns the shaft 108 with the central opening 127 of the bonded    washer 126, inserts the tip 118 through the central opening 127 and    then positions the tip 118 into the pilot hole 144.-   4) Finally, the installer engages an appropriate drive socket to    drive head 122 and uses a power driver to secure a wood threaded    roof fastening portion 110 of shaft 108 into the roof layers    following the pilot hole 144 to finally engage with the wood rafter    beam 142. As the installer drives the hanger bolt 102 into the roof,    eventually shoulder surface 123 of the flange 124 will contact the    first upper surface of the bonded washer 126 and urge it downward    (as the hanger bolt 102 drives itself into the roof during its    driven clockwise rotation) until rubber layer 128 becomes pressed    firmly against the outer layer of shingles 134. The rubber layer 128    will compress against the shingles 134 and form an effective seal    with the roof surface so that rain water (or any water) cannot    penetrate any of the roof layers along the installed hanger bolt    102. The concave shape of the washer 126 will help compress the    rubber layer 128 along the periphery of the circular layer. This    will ensure a tight water seal between washer 126 and the shingles    134.

Once all the mounting assemblies 100 are installed into the roof at theprescribed locations, the anchor portion 114 of each installed mountingassembly 100 remains accessible above the roof surface and can be usedto secure a roof mounted structure including any appropriate rackingmember or frame structure 150 (shown in FIG. 5). A nut (not shown) andappropriate washers and/or lock washers can be used to secure theracking members or frame structures to each installed hanger bolt 102 bythreadedly engaging included anchoring threads with a roof mountedstructure.

As can be seen from the above, the described mounting assembly 100 caninclude as few as two parts (if a bonded washer is used, as ispreferred); a hanger bolt 102 and a bonded washer 126. The use of anintegral flange 124 obviates the need for any stop nuts that had beenused in prior art mount systems. An integral flange 124 allows thepresent mount system to remain simple to manufacture and assemble, andalso easy to install since there are fewer parts to assemble and keeptrack of. Once installed, racking members can be then secured to theaccessible machine threads of the anchor portion 114.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiments but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims, which scope is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures as is permitted under the law.

What is claimed is:
 1. An apparatus for securing a roof-mountedstructure comprising: a roof; a shaft extending along a longitudinalshaft axis and including a first end opposing a second end; the firstend including a roof fastening portion secured within the roof; thesecond end including a drive part and an anchor portion for securing theroof-mounted structure to the shaft; the shaft including a radiallyprojecting shoulder surface disposed between the first and second endsand oriented toward the first end; and a washer of sufficient size toform a watertight seal with a surface of the roof disposed on the shaftand positioned on the surface of the roof between the surface of theroof and the shoulder surface, the shoulder surface engaging the washerto urge the washer into sealing contact with the surface of the roof. 2.The apparatus of claim 1, further comprising: the washer including arigid first washer having a first surface opposing a second surface anddefining a through aperture sized to receive the roof fastening portionof the shaft, wherein at least a portion of the first surface is engagedby the shoulder surface.
 3. The apparatus of claim 2, wherein the firstwasher has a conical cross section.
 4. The apparatus of claim 2, furthercomprising: the washer including a compliant second sealing washerpositioned between the first washer and the surface of the roof toprovide the sealing contact with the surface of the roof.
 5. Theapparatus of claim 1, wherein the first end of the shaft has a firstshaft diameter adjacent the shoulder surface, further comprising: aflange with a flange diameter greater than the first shaft diameter,wherein the flange defines the shoulder surface.
 6. The apparatus ofclaim 5, wherein the flange is integrally formed with the shaft and theshoulder surface is a planar surface orthogonal to the shaft axis. 7.The apparatus of claim 1, wherein the drive part is a screw drive,further comprising: the roof fastening portion having external woodscrew threads configured for threaded engagement with the roof.
 8. Theapparatus of claim 7, further comprising: the screw drive having a headconfigured for engagement with a drive socket.
 9. The apparatus of claim7, wherein the wood screw threads include a thread cutting portion at aterminal part of the first end.
 10. The apparatus of claim 1, furthercomprising: the anchor portion having machine screw anchoring threadsconfigured for threaded engagement with the roof-mounted structure. 11.The apparatus of claim 10, wherein the anchoring threads are included onan exterior of the second end along the anchoring portion.
 12. Theapparatus of claim 1, wherein the washer is a concave bonded washerhaving a rubber layer urged into sealing contact with the surface of theroof.
 13. The apparatus of claim 12, wherein an outer diameter of thewasher is approximately 3 inches and wherein the rubber layer is urgedinto sealing contact with the surface of the roof around a periphery ofthe washer.
 14. The apparatus of claim 1, wherein: an outer diameter ofthe washer is approximately 3 inches.
 15. A method of securing a roofmounted structure to a roof having at least one roof tile overlying aroof support structure using a shaft and a washer, the shaft including aroof fastening portion disposed at a first end of the shaft, a drivepart and an anchor portion disposed at a second end of the shaftopposing the first end, and an integrally formed radially projectingshoulder surface disposed between the first and second ends and orientedtoward the first end, the washer having of sufficient size to form awatertight seal with the roof and having a first surface opposing asecond surface and defining a through aperture sized to receive the rooffastening portion of the shaft, the method comprising: positioning thesecond surface of the washer in contact with an outer surface of the atleast one roof tile and axially aligning the roof fastening portion withthe through aperture; engaging the drive part to drive the rooffastening portion through the at least one roof tile and into the roofsupport structure such that the shoulder surface engages the firstsurface of the washer to urge the washer towards the outer surface ofthe at least one roof tile and provide a watertight seal between thesecond surface and the outer surface of the at least one roof tile; andsecuring a roof mounted structure to the anchor portion.
 16. The methodof claim 15, wherein: the roof fastening portion includes externalthreads configured for threaded engagement with the roof; the drive partincludes a screw drive; and the step of engaging the drive part furthercomprises rotatably engaging the screw drive to drive the roof fasteningportion through the roof tiles and into the roof support structure. 17.The method of claim 15, wherein: the anchor portion includes machinescrew threads; and the step of securing the roof mounted structurefurther comprises threadingly engaging the roof-mounted structure withthe machine screw threads.
 18. An apparatus for securing a roof-mountedstructure comprising: a roof having a plurality of roof tiles overlyinga roof support structure; a shaft having a shaft diameter extendingalong a longitudinal shaft axis and including a first end opposing asecond end; the first end including a roof fastening portion havingexternal wood threads threadedly engaged with the roof supportstructure; the second end including a screw drive and an anchor portion,the screw drive having a head with a head diameter equal to or less thanthe shaft diameter and configured for engagement with a drive socket andthe anchor portion having exterior machine screw threads configured forthreaded engagement with the roof-mounted structure; a flange integrallyformed with the shaft and disposed between the first and second ends,the flange projecting radially from the shaft to define a shouldersurface oriented toward the first end; and a washer having an outerdiameter of at least approximately 3 inches and having a first surfaceopposing a second surface forming a rubber layer, the washer defining athrough aperture sized to receive the roof fastening portion of theshaft, the washer disposed on the shaft and positioned on an outersurface of at least one of the plurality of roof tiles between the outersurface of the at least one roof tile and the shoulder surface, whereinat least a portion of the first surface is engaged by the shouldersurface such that the second surface is urged into sealing contact withthe outer surface of the at least one roof tile to provide a watertightseal between the washer and the outer surface of the at least one rooftile.
 19. The apparatus of claim 18, wherein the washer is a concavebonded washer.